The present invention is drawn to an improved gas injection nozzle design for use in a swirling tank reactor used in the degassing of molten metal with a fluxing gas.
An improved method and apparatus for degassing molten metal is disclosed in U.S. Pat. No. 4,177,066 to Joseph A. Clumpner and assigned to the assignee of the instant invention. The disclosure in the aforenoted patent teaches degassing molten metal using an apparatus comprising a swirling tank reactor wherein molten metal is tangentially introduced into the reactor so that the molten metal flows in a swirling rotating fashion as the metal passes from the inlet of the reactor to the outlet thereof. In order to achieve the desired swirling flow of molten metal from the metal inlet to the metal outlet of the reactor, it is required that the metal inlet be positioned with respect to the chamber wall of the reactor in such a manner as to tangentially introduce the liquid into the reactor. In a preferred embodiment, the swirling tank reactor comprises a first elongated substantially cylindrical sidewall portion and a second downwardly converging sidewall portion beneath the first substantially cylindrical wall portion. Fluxing gas inlet nozzles penetrate the converging wall portion at different heights thereof so as to optimize fluxing gas bubble dispersion through the entire melt as it passes from the inlet of the reactor to the outlet thereof. By positioning the nozzles at different heights in the converging wall portion, the fluxing gas nozzles are in turn located at various distances from the center axis of the swirling tank reactor thereby maximizing fluxing gas bubble dispersion. The specific details of the various embodiments of swirling tank reactors and nozzle locations disclosed in U.S. Pat. No. 4,177,066 may readily employ the improved gas injection nozzle design of the present invention and the disclosure of U.S. Pat. No. 4,177,066 is incorporated herein by reference.
While the above-noted swirling tank reactors disclosed in U.S. Pat. No. 4,177,066 are superior to other known prior art inline degassing apparatuses, a number of problems have been encountered with fluxing gas nozzle designs. In particular, metal leakage from the reactor around the nozzle tip has been experienced. In addition, a problem has been encountered with leakage in the fluxing gas delivery line itself. Finally, it has been found that the nozzles tend to break off when they project through the chamber wall and into the tank proper.
Accordingly, it is a primary object of the present invention to provide an improved gas injection nozzle design for delivering a gaseous material which is free of leakage in the gas delivery line.
It is the principal object of the present invention to provide an improved gas injection nozzle design for use in a swirling tank reactor used in the degassing of molten metal with a fluxing gas.
It is a particular object of the present invention to provide an improved gas injection nozzle design for use in a swirling tank reactor used in the degassing of molten metal wherein leakage from the reactor around the nozzle tip is prohibited.
It is still a further object of the present invention to provide an improved gas injection nozzle design provided with the improvements as aforesaid which is convenient and inexpensive to utilize.
Further objects and advantages of the present invention will appear hereinbelow.